Method and apparatus for scanning image

ABSTRACT

A method and an apparatus for scanning an image. The method includes moving an image sensor; determining whether a side of a rectangular periphery is detected; detecting first and second reference points representing both end points of the side; receiving and scanning an image between the first and second reference points; deciding whether the side opposite to the side is detected; and stopping scanning the image, and stopping the image sensor.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the priority of Korean Patent Application No. 2002-82379, filed on Dec. 23, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to image formation using an image sensor, and more particularly, to a method and an apparatus for an image processing apparatus which scans an image of an original document having a rectangular shape, line by line.

[0004] 2. Description of the Related Art

[0005] In general, an image processing apparatus, such as an image scanner, facsimile, digital copier, or the like includes a central processing portion, an image sensor, an image reading portion, a memory portion, a computer interfacing portion, an information input/output portion and the like.

[0006] The central processing portion controls the overall operation of the above-mentioned devices. Particularly, the central processing portion stores image data acquired by the image sensor in the memory portion, and controls data conversion.

[0007] The image sensor emits light of a light source to an original document, and converts reflected light into an electrical output with a CCD (charge coupled device) and a CIS (contact image sensor).

[0008] The image reading portion causes an image converted into the electrical output to be stored in a data memory device such as a hard disk of a computer.

[0009] The memory portion stores image data transmitted from the image reading portion according to the control of the central processing portion, and stores other program data required for control operations of the central processing portion.

[0010] The computer interfacing portion acts as a path to transmit read image data to the computer.

[0011] The information input/output portion has a plurality of keys, applies data to the central processing portion when a predetermined key is selected, and displays operation status of the image processing apparatus controlled by the central processing portion.

[0012] However, a conventional image processing apparatus can process an image in a manner in which the size of an original document is sensed and the scanned image is equal to the sensed area of the original document. First, in the sensing of the size of the original document, after the periphery of the original document is exhibited clearly by lowering the resolution of the whole area of the image in a mode called a free scanning mode, information concerning the size of the original document is acquired. Subsequently, the size of the read image is the same as the size of the original document. The size of the original document is based on the information concerning the size of the original document while the resolution designated by a user is taken into consideration.

[0013] Therefore, in order to acquire an image in the conventional art, the image can be acquired after the scanning operation of the image is performed twice. Consequently, when a small document such as a business card or post card is copied, there is no way to scan the small document without preliminary free scanning, and when the free scanning is performed, the free scanning causes time consumption equal to the time required for the free scanning.

SUMMARY OF THE INVENTION

[0014] Accordingly, it is an aspect of the present invention to provide a method of scanning an image, which is capable of scanning an image in a single scan by detecting the periphery of an original document.

[0015] It is another aspect of the present invention to provide an apparatus to scan an image, which is capable of performing the above method of scanning an image.

[0016] Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

[0017] The foregoing and/or other aspects are achieved by providing a method of scanning with an image processing apparatus which has an image sensor, and performs the scanning by reading an original document having a rectangular periphery line by line, the method including: moving the image sensor; determining whether a first side of the rectangular periphery is detected by the image sensor; detecting first and second reference points representing first and second end points of the first side; receiving and scanning an image between the first and second reference points; determining whether a second side of the document opposite to the first side is detected; and stopping the scanning, and stopping the image sensor.

[0018] The foregoing and/or other aspects are also achieved by an apparatus to scan an original document having a rectangular periphery line by line, the apparatus including: an image sensor receiving an image of the original document; a periphery detecting portion to detect a first side of the rectangular periphery or a second side opposite to the first side in response to the input image, and outputs a result of the detection; a reference point detecting portion to detect first and second reference points corresponding to first and second end points of the first side according to the detection results, and outputs the detected first and second reference points; an image scanning portion which scans and stops scanning the image between the detected first and second reference points; and an image sensor driving portion to move the image sensor in response to an image-scanning request signal, or stop the image sensor in response to the results of the detection.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

[0020]FIG. 1 is a flowchart describing of a method of scanning an image according to an embodiment of the present invention;

[0021]FIG. 2 is a diagram showing an original document laid on a flatbed as an example to describe the method shown in FIG. 1 in detail;

[0022]FIG. 3 is a flowchart for describing operation 12 shown in FIG. 1;

[0023]FIG. 4 is a flowchart for describing operation 16 shown in FIG. 1;

[0024]FIG. 5 is a flowchart for describing operation 18 shown in FIG. 1;

[0025]FIG. 6 is a block diagram of an apparatus to scan an image according to an embodiment of the present invention;

[0026]FIG. 7 is a block diagram of a periphery detecting portion shown in FIG. 6; and

[0027]FIG. 8 is a block diagram of an image scanning portion shown in FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures.

[0029]FIG. 1 is a flowchart to describe a method of scanning an image according to an embodiment of the present invention. Referring to FIG. 1, a method of scanning an image includes detecting one side or the opposite side of the periphery of an original document, and scanning an image or stopping scanning the image (operations 10, 12, 14, 16, 18 and 20).

[0030] First, an image sensor is moved (operation 10). While the image sensor is moved below a flatbed, the image sensor emits light of a light source toward the original document and detects light reflected from the original document.

[0031] After operation 10, it is determined whether or not the one side of the rectangular periphery of the original document is detected (operation 12). A document the size of which is relatively smaller than the size of the flatbed (such as a small calling card, postcard, or the like) can be exemplified as an original document having a rectangular periphery. The periphery of a rectangle has 4 sides. Therefore, in operation 12, it is determined whether or not the one side of the four sides is detected. When it is determined that the one side of the rectangular periphery is not detected, operation 10 follows operation 12.

[0032]FIG. 2 is a diagram showing the original document laid on the flatbed, and FIG. 3 is a flowchart for describing operation 12 shown in FIG. 1. The operation 12 shown in FIG. 3 includes operations 70 and 72 of deciding whether or not a first straight-line image, a second straight-line image, and a third straight-line image are detected.

[0033] First, it is determined whether or not a first straight-line image is detected (operation 70). Four sides 42, 44, 46, and 48 of the original document 40 shown in FIG. 2 are shown as straight lines when displayed as an image. When the first straight-line image is detected, the first straight-line image may be an image of the one side 42 of the periphery of the original document 40. Therefore, referring to FIG. 2, it can be seen that the first straight-line image detected by an image sensor 30 must be an image of the one side 42 of the periphery of the original document. Even though it cannot be determined whether or not the first straight-line image is the one side 42 of the periphery of the original document until operation 72 is performed, operation 70 is still necessary to decide whether or not the first straight-line image is the one side 42 of the periphery of the original document. When it is decided that the first straight-line image is not detected, operation 10 follows operation 70. Since when it is decided that the first straight-line image is not detected, it means that the image sensor 30 has not reached the original document 40 yet, the image sensor 30 continues to move toward the original document 40.

[0034] However, when the first straight-line image is detected, it is determined whether or not the second and third straight-line images are detected to be greater than a predetermined length at both end points of the first straight-line image in a moving direction of the image sensor 30 (operation 72). The both end points of the first straight-line image are indicated by reference numerals 50 and 52, as shown in FIG. 2. That is, the both end points 50 and 52 of the first straight-line image are both end points of the one side 42 of the periphery of the original document 40. It can be seen that the second and third straight-line images represent the images of the other two sides 44 and 46 of the periphery of the original document 40. Whether or not the second and third straight-line images are portions of the periphery of the original document 40 can be decided by deciding whether or not the second and third straight-line images are detected at the both end points 50 and 52 of the first straight-line image.

[0035] When it is determined that the second and third straight-line images are detected at the both end points 50 and 52 of the first straight-line image, operation 14 follows operation 72. On the other hand, when it is determined that the second and third straight-line images are not detected at the both end points 50 and 52 of the first straight-line image, operation 10 follows operation 72. If the second and third straight-line images are not detected at the both end points 50 and 52 of the first straight-line image indicates that the first straight-line image is not an image of the one side 42 of the original document 40, but is only a general straight-line image. Therefore, the image sensor 30 does not reach the original document 40 yet.

[0036] When it is determined that the one side is detected in operation 12, a first reference point and a second reference point representing the both end points 50 and 52 of the one side 42 are detected (operation 14). As shown in FIG. 2, the both end points 50 and 52 of the one side 42 are set to be the first and second reference points, respectively. Therefore, the first reference point is indicated by reference numeral 50, and the second reference point is indicated by reference numeral 52.

[0037] After operation 14, an image between the first reference point 50 and the second reference point 52 is inputted and read (operation 16). While the image sensor 30 moves, the image sensor 30 reads the image between the first reference point 50 and the second reference point 52, and scanning of the read image is completed.

[0038]FIG. 4 is a flowchart for describing operation 16 shown in FIG. 1. The operation 16 includes the operations (80 and 82) of detecting a third reference point 54 and a fourth reference point 56, and scanning an outstanding- periphery image and a general image.

[0039] First, the third reference point 54 having a predetermined distance from the first reference point 50 is detected, and the fourth reference point 56 having the predetermined distance from the second reference point 54 is detected (operation 80). The third reference point 54 and the fourth reference point 56 are designated on the one side 42 to have a predetermined distance “a” from the first and second reference points 50 and 52, respectively.

[0040] After operation 80, an image between the first and third reference points 50 and 54 and an image between the second and fourth reference points 52 and 56 are scanned as outstanding-periphery images of the original document 40, and an image between the third and fourth reference points 54 and 56 is scanned as a general image (operation 82). The outstanding-periphery image is an image which is clearly shaded so that the shape of the periphery of the original document 40 can be definitely expressed. Therefore, the third reference point 54 is positioned near the first reference point 50 so that an actual scanning portion of the original document which a user wants to scan cannot be infringed. Being similar to the third reference point 54, the fourth reference point 56 is positioned near the second reference point. What is called the general image is an image, i.e., a predetermined area of the original document which is scanned according to the resolution, shades, and the like which are set by a user. Therefore, an image required by the user can be obtained by scanning the image between the third and fourth reference points 54 and 56.

[0041] In addition, while the above scanning is performed in operation 82, a predetermined line image is scanned as an outstanding-periphery image after the one side is detected, and an image following the predetermined line image is scanned as a general image. The predetermined line image represents an image of a portion which has a width “b” and is shaded so that the one side 42 can be definitely expressed. The width “b” of the predetermined line image has the same value as the distance “a” between the first and third reference points 50 and 54, or the distance “a” between the second and fourth reference points 52 and 56.

[0042] After operation 16, it is determined whether or not the opposite side of the one side 42 is detected (operation 18). As shown in FIG. 2, the one side 42 and the opposite side 48 face each other. When it is determined that the opposite side 48 is not detected, operation 16 follows operation 18.

[0043]FIG. 5 is a flowchart for describing operation 18 shown in FIG. 1. The operation 18 includes steps 90 and 92 of deciding whether or not the fourth straight-line image and the second and third straight-line images are detected.

[0044] First, it is determined whether or not the fourth straight-line image is detected (operation 90). Referring to FIG. 2, when the fourth straight-line image is detected, the fourth straight-line image may be the side 48 opposite to the one side 42 of the original document 40. Even though it cannot be determined whether or not the fourth straight-line image is the opposite side 48 until operation 92 is performed, operation 90 is still necessary to decide whether or not the fourth straight-line image is the opposite side 48. When it is determined that the fourth straight-line image is not detected, operation 16 follows operation 90.

[0045] However, when it is determined that the fourth straight-line image is detected, it is determined whether or not the second and third straight-line images are detected more than a predetermined length from both ends of the fourth straight-line image in the moving direction of the image sensor 30 (operation 92). The predetermined length is a length long enough to decide whether or not the second and third straight-line images are straight lines. The both end points of the fourth straight-line image are indicated by reference numerals 58 and 60, as shown in FIG. 2. That is, the both end points 58 and 60 of the fourth straight-line image represent both end points of the opposite side 48 of the periphery of the original document. Whether or not the fourth straight line is a portion of the periphery of the original document 40 can be decided by deciding whether or not the second and third straight-line images are detected at the both end points 58 and 60 of the fourth straight-line in the moving direction of the image sensor 30.

[0046] When it is determined that the second and third straight-line images are detected at the end points 58 and 60 of the fourth straight-line in the moving direction of the image sensor 30, operation 16 follows operation 92. That is, the fact that the second and third straight-line images are detected at the both end points 58 and 60 of the fourth straight-line image means that the fourth straight-line image is not an image of the opposite side 48 of the original document 40, but a general straight-line image. On the other hand, when it is decided that the second and third straight-line images are not detected at the both end points 58 and 60 of the fourth straight-line in the moving direction of the image sensor, operation 20 follows operation 92. Operation 20 includes stopping the image sensor and the scanning of the image. That is, the fact that the second and third straight-line images are not detected at the both end points 58 and 60 of the fourth straight-line image means that the fourth straight-line image is an image of the opposite side 48 of the original document 40.

[0047] When it is determined that the opposite side 48 is detected in operation 18, scanning of the image is stopped, and the image sensor is stopped from moving. Since the fact that the opposite side 48 is detected means that the marginal portion of the periphery of the original document is detected, scanning of the image is stopped, and the image sensor is stopped from moving.

[0048] Now, an apparatus to scan an image according to the embodiment of the present invention will be described with reference to the attached drawings.

[0049]FIG. 6 is a block diagram of the apparatus, which includes an image sensor driving portion 100, an image sensor 120, a periphery detecting portion 140, a reference point detecting portion 160, and an image scanning portion 180.

[0050] In order to perform operation 10 and operation 20, the image sensor driving portion 100, responding to an image-scanning request signal, moves the image sensor 120, and, responding to a detected result inputted from the periphery detecting portion 140, stops the image sensor 120. Responding to the image-scanning request signal inputted via an input terminal IN1, the image sensor driving portion 100 moves the image sensor 120 below a flatbed. In addition, responding to the detected result inputted from the periphery detecting portion 140, the image sensor driving portion 100 stops the image sensor 120.

[0051] The image sensor 120 receives an image of an original document. The image sensor 120 emits light from a light source toward the original document, receives reflected light, and outputs the received light image to the periphery detecting portion 140.

[0052] In order to perform operations 12 and 18, the periphery detecting portion 140, responding to the image inputted from the image sensor 120, detects one side of a rectangular periphery of the original document 40 or the opposite side 48, and outputs the detected results. The periphery detecting portion 140, responding to the image inputted from the image sensor 120, detects the one side 42 of the rectangular periphery, and outputs the detected results to the reference point detecting portion 160. In addition, the periphery detecting portion 140 detects the opposite side 48 of the rectangular periphery, and outputs the detected result to the image sensor driving portion 100 and the image scanning portion 180.

[0053]FIG. 7 is a block diagram for describing the periphery detecting portion 140. The periphery detecting portion 140 includes a first-straight-line-image checking portion 200, a second-straight-line-image checking portion 220, a third-straight-line-image checking portion 240, and a fourth-straight-line-image checking portion 260.

[0054] In order to perform operation 70, the first-straight-line-image checking portion 200 checks the first straight line corresponding to the one side 42, and outputs the checked results as a first check signal. The first-straight-line-image checking portion 200 receives an image from the image sensor 120 via an input terminal IN2, checks whether or not the received image is the first straight line image corresponding to the one side 42 shown in FIG. 2, and outputs the checked results as the first check signal to the second-straight-line-image checking portion 220.

[0055] In order to perform operation 72, the second-straight-line-image checking portion 220, responding to the first check signal, checks whether or not the second and third straight line images are detected to be greater than the predetermined length at both end points 50 and 52 of the first straight line image in the moving direction of the image sensor 120, and outputs the checked results as a second check signal. The second-straight-line-image checking portion 220, responding to the first check signal inputted from the first-straight-line-image checking portion 200, checks the second and third straight line images, and outputs the checked results as the second check signal via an output terminal OUT2.

[0056] In order to perform operation 90, the third-straight-line-image checking portion 240 checks the fourth straight line image corresponding to the opposite side 48, and outputs the checked results as a third check signal. The third-straight-line-image checking portion 240 receives an image from the image sensor 120 via the input terminal IN2, checks whether or not the received image is the fourth straight line image corresponding to the opposite side 48 shown in FIG. 2, and outputs the checked results as the third check signal to the fourth-straight-line-image checking portion 260.

[0057] In order to perform operation 92, the fourth-straight-line-image checking portion 260, responding to the third check signal, checks whether or not the second and third straight line images are detected to be greater than the predetermined length at the both end points 58 and 60 of the fourth straight line image in the moving direction of the image sensor 120, and outputs the checked results as a fourth check signal. The fourth-straight-line-image checking portion 260, responding to the third check signal inputted from the third-straight-line-image checking portion 240, checks the second and third straight line images, and outputs the checked results as the fourth check signal via an output terminal OUT3.

[0058] In order to perform operation 14, the reference point detecting portion 160, responding to the detected results from the periphery detecting portion 140, detects the first reference point 50 and the second reference point 52 which represent the both end points of the one side, and outputs the detected first and second reference points 50 and 52. The reference point detecting portion 160 receives the detected results of the one side 42 shown in FIG. 2 from the periphery detecting portion 140, detects the first reference point 50 and the second reference point 52 which represent the both end points of the one side 42, and outputs the detected first and second reference points 50 and 52 to the image scanning portion 180.

[0059] In order to perform operation 16, the image scanning portion 180 scans and stops scanning an image between the detected first and second reference points. The image scanning portion 180, responding to the detected first and second reference points 50 and 52 inputted from the reference point detecting portion 160, outputs a signal to scan the image between the first and second reference points 50 and 52 via an output terminal OUT1. In addition, the image scanning portion 180, responding to the detected results from the periphery detecting portion 140, stops scanning the image between the first and second reference points 50 and 52.

[0060]FIG. 8 is a block diagram of the image scanning portion 180, which includes a detailed-reference-point detecting portion 300, and a classified image scanning and processing portion 320.

[0061] In order to perform operation 80, the detailed-reference-point detecting portion 300 detects the third reference point 54 having the predetermined distance from the first reference point 50, and the fourth reference point 56 having the predetermined distance from the second reference point 52. The detailed-reference-point detecting portion 300 receives the first reference point 50 from the reference point detecting portion 160 via an input terminal IN3, detects the third reference point 54 having the predetermined distance from the first reference point 50, and outputs the detected third reference point 54 together with the first reference point 50 to the classified image scanning and processing portion 320. The detailed-reference-point detecting portion 300 receives the second reference point 52 from the reference point detecting portion 160 via the input terminal IN3, detects the fourth reference point 56 having the predetermined distance from the second reference point 52, and outputs the detected fourth reference point 56 together with the second reference point 52 to the classified image scanning and processing portion 320.

[0062] In order to perform operation 82, responding to the detected first, second, third, and fourth reference points 50, 52, 54 and 56, the classified image scanning and processing portion 320 scans the image between the first and third reference points 50 and 54 and the image between the second and fourth reference points 52 and 56 as the outstanding-periphery image, and scans the image between the third and fourth reference points 54 and 56 as the general image. Responding to the first and third reference points 50 and 54 inputted from the detailed-reference-point detecting portion 300, the classified image scanning and processing portion 320 scans the image between the first and third reference points 50 and 54 as the outstanding-periphery image. In addition, responding to the second and fourth reference points 52 and 56 inputted from the detailed-reference-point detecting portion 300, the classified image scanning and processing portion 320 scans the image between the second and fourth reference points 52 and 56 as the outstanding-periphery image. In addition, responding to the third and fourth reference points 54 and 56 inputted from the detailed-reference-point detecting portion 300, the classified image scanning and processing portion 320 scans the image between the third and fourth reference points 54 and 56 as the general image. The classified image scanning and processing portion 320 outputs the scanned outstanding-periphery image and the general image of the original document via an output terminal OUT4.

[0063] In addition, the classified image scanning and processing portion 320 scans the predetermined line of the original document as the outstanding-periphery image after the one side is detected, and scans the image after the predetermined line as the general image.

[0064] As described above, the method and the apparatus to scan an image according to the embodiments of the present invention are capable of scanning an image by moving the image sensor once without scanning an original document to detect the size of the original document in advance in a flatbed type image processing apparatus, and is capable of markedly shortening image scanning time by preventing the image sensor from moving beyond the area of the original document to be scanned.

[0065] Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in the embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. 

What is claimed is:
 1. A method of scanning with an image processing apparatus which has an image sensor, and performs the scanning by reading an original document having a rectangular periphery line by line, the method comprising: moving the image sensor; determining whether a first side of the rectangular periphery is detected by the image sensor; detecting first and second reference points representing first and second end points of the first side; receiving and scanning an image between the first and second reference points; determining whether a second side of the document opposite to the first side is detected; and stopping the scanning when it is determined that the second side is detected, and stopping the image sensor.
 2. The method according to claim 1, wherein the determining whether the first side is detected comprises: determining whether a first straight line image corresponding to the first side is detected, wherein the moving of the image sensor occurs after the determining that the first straight line image is not detected; and determining whether second and third straight line images are detected further than a predetermined distance from the first and second end points of the first straight line image in a moving direction of the image sensor, wherein the detecting of the first and second reference points occurs after the determining that the second and third straight line images are detected, and the moving of the image sensor occurs after the determining that the second and third straight line images are not detected.
 3. The method according to claim 1, wherein a starting point and an ending point of the first side correspond to the first and second end points of the first straight line image.
 4. The method according to claim 1, wherein the receiving and scanning of the image comprises: detecting a third reference point having a predetermined distance from the first reference point, and a fourth reference point having the predetermined distance from the second reference point; and scanning between the first and third reference points and between the second and fourth reference points as an outstanding- periphery portion of the image, and scanning between the third and fourth reference points as a general portion of the image.
 5. The method according to claim 4, wherein the scanning as the outstanding-periphery portion and the general portion comprises scanning a predetermined line as the outstanding-periphery portion after the detecting of the first side, and the general portion is scanned after the scanning of the predetermined line.
 6. The method according to claim 1, wherein the determining whether the second side is detected comprises: determining whether a fourth straight line image is detected, wherein the receiving and scanning of the image occur after determining that the fourth straight line image is not detected; and determining whether second and third straight line images are detected further than a predetermined distance from first and second end points of the fourth straight line image in a moving direction of the image sensor, wherein the receiving and scanning of the image between the first and second reference points occur after the determining that the second and third straight line images are detected, and the stopping of the scanning and the image sensor occurs after the determining that the second and third straight line images are not detected, wherein the fourth straight line image corresponds to the second side of the rectangular periphery.
 7. The method according to claim 2, wherein the second and third straight-line images respectively correspond to the second side and a third side of the document.
 8. The method according to claim 2, further comprising determining whether the detected second and third straight line images are at the first and second end points, wherein the moving of the image sensor occurs after the determining that the second and third straight line images are not at the first and second end points.
 9. An apparatus to scan an original document having a rectangular periphery line by line, the apparatus comprising: an image sensor receiving an image of the original document; a periphery detecting portion to detect a first side of the rectangular periphery or a second side opposite to the first side in response to the received image, and outputs the a result of the detection of the first side; a reference point detecting portion to detect first and second reference points corresponding to first and second end points of the first side according to the results of the detection of the first and second end points, and outputs the detected first and second reference points; an image scanning portion which scans and stops scanning the image between the detected first and second reference points; and an image sensor driving portion to move the image sensor in response to an image-scanning request signal, or to stop the image sensor in response to the results of the detection of the second side.
 10. The apparatus according to claim 9, wherein the periphery detecting portion comprises: a first-straight-line-image checking portion checking a first straight line image corresponding to the first side, and outputting results of the checking of the first straight line image as a first check signal; a second-straight-line-image checking portion to check whether second and third straight line images are detected further than a first predetermined distance from the first and second end points of the first straight line image in a moving direction of the image sensor in response to the first check signal, and to output the results of the checking of the second and third straight line images as a second check signal; a third-straight-line-image checking portion checking a fourth straight line image, and outputting the results of the checking of the fourth straight line image as a third check signal; and a fourth-straight-line-image checking portion to check whether the second and third straight line images are detected further than a second predetermined length from end points of the fourth straight line image in a moving direction of the image sensor in response to the third check signal, and output the results of the checking whether the second and third straight line images are detected as a fourth check signal.
 11. The apparatus according to claim 10, wherein the image scanning portion s comprises: a detailed-reference-point detecting portion detecting a third reference point having a third predetermined distance from the first reference point and a fourth reference point having the third predetermined distance from the second reference point; and a classified image scanning and processing portion to respond to the detected first, second, third, and fourth reference points, scan between the first and third reference points and between the second and fourth reference points as an outstanding-periphery portion of the image of the original document, and to scan between the third and fourth reference points as a general portion of the image of the original document.
 12. The apparatus according to claim 9, wherein the classified image scanning and processing portion scans a predetermined line as the outstanding-periphery image after the first side is detected, and scans past the predetermined line in the moving direction of the image sensor as the general portion.
 13. The apparatus according to claim 9, further comprising a flatbed, wherein the image sensor is moved below the flatbed.
 14. A method comprising: moving an image sensor a single time from a first side of a document to a second side of the document opposite the first side; detecting a size of the document during the moving; and scanning the document during the moving.
 15. The method according to claim 14, wherein the scanning comprises scanning the document line by line.
 16. The method according to claim 14, wherein the scanning comprises scanning a rectangular document.
 17. The method according to claim 14, further comprising: detecting second and third straight line images; and determining whether the second and third straight line images are respectively second and third sides of the document.
 18. The method according to claim 17, wherein the determining whether the second and third straight line images are second and third sides comprises: detecting first and second end points of the first side; and determining whether the second and third straight line images are further than a predetermined distance from the first and second end points.
 19. The method according to claim 14, wherein the moving comprises moving the image sensor only within an area of the scanned document. 